hi candy, i will add this. dont be scared, and dont talk yourself out of it. you have already done it once! and that was because the sub obeyed her Masters command. it wasnt you thinking oh, oh no, what shall i do? He has told me to cum but i cant!? obviously you trust Him otherwise He wouldnt be your Master. so trust Him! let yourself go, that is what being a sub is all about. let Him have the control, it is not your orgasm, it is His. and so it will happen.
and you will love it!!!
and the feeling of submisiveness will just amaze you.

enjoy

luck and luv from the girl